Calcium Concentration Microdomains
A question often posed in the field of neuroscience is that of the mechanism by which extracellular calcium releases transmitter from the presynaptic terminal (Katz & Miledi, 1965). Results from two decades ago, indicated that spatially restricted zones of transient high calcium concentration in the neuronal cytosol, could be produced as a result of the opening of voltage gated calcium channels in the plasmalemma (Llinás, 1977). This hypothesis together with the finding that the latency for calcium activation of transmitter release was in the range of 200 msec, suggests that calcium, at the presynaptic active zone, acts at a location very close to the release site and that the calcium channels themselves might be part of this active zone (Llinés, 1977).
KeywordsActive Zone Transmitter Release Presynaptic Terminal Voltage Gated Calcium Channel Presynaptic Spike
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